This invention relates to irrigation equipment and particularly to water pressure regulators for use with sprinkler devices.
It is well known to use fluid pressure regulators on irrigation systems in order to provide constant outlet pressure over a wide range of inlet pressures. The need for such regulators is particularly acute in low pressure systems because a slight variation in pressure causes a much greater variation in discharge than the same system operating at high pressure.
The assignee of this invention currently manufactures and sells a fluid pressure regulator of the flow through type, having an inlet at one end of a tubular housing and an outlet at the other end of the tubular housing. An annular seat, supported by a plurality of radial struts centrally of the flowpath, is fixed within the housing and is adapted to be engaged by a tubular plunger which is spring biased away from the seat (in the direction of fluid flow) so that under normal conditions, maximum flow through the regulator is permitted. In the event of a pressure surge, the plunger is moved by back pressure at the regulator outlet, within a diaphragm chamber, against the action of the spring (and against atmospheric pressure), toward the regulator seat, thereby decreasing the flow through the regulator. As the outlet pressure subsequently decreases, the plunger moves in an opposite direction under the influence of the spring. The plunger thus continuously seeks an equilibrium position where the opposed pressures on the piston are substantially equal. See, for example, commonly owned U.S. Pat. No. 5,257,646. Regulators of this type, however, are prone to clogging by grass and other fibrous debris that tends to “hairpin' about the radial webs or struts supporting the seat in the center of the flowpath. It would therefore be desirable to eliminate any radially oriented webs or struts in pressure regulator devices to minimize the potential for clogging.